1. Field of the Invention
The present invention is generally related to a magnet rotor assembly that is used in conjunction with a flywheel to generate electrical current for use by an internal combustion engine and, more particularly, to a magnet rotor assembly in which the individual permanent magnets are solidly embedded within a non magnetic ring which is shaped to be permanently received within a flywheel of an internal combustion engine.
2. Description of the Prior Art
Many different types of electrical generators are known for use with internal combustion engines to provide electrical current for use by the internal combustion engine, primarily in its battery charging and ignition circuits. These electrical generating systems typically use a plurality of permanent magnets in conjunction with a rotatable flywheel of the internal combustion engine to induce current flow through a plurality of windings disposed proximate the circular paths of the permanent magnets. These electrical generating systems are made by numerous different processes and are of various different shapes and configurations.
U.S. Pat. No. 4,241,620, which issued to Pichl et al on Dec. 30, 1980, describes a balance wheel for rotating machines, especially combustion engines, including outboard motors. Typically, such balance wheels or flywheels have been manufactured from different non-ferrous metals as zinc or aluminum alloys, and in one embodiment they have the shape of an inverted pot having low side walls. On the inner side of the walls balance wheel magnets, such as permanent magnets for the ignition or generator system of the motor, are attached and the other elements of the ignition or generator systems are disposed outwardly around the output shaft of the engine and inside the pot. However, for obtaining a suitable magnetic field, the permanent magnets are not attached directly to the balance wheel of a non-magnetic material, but on a ring of magnetic material, for instance steel, which in its turn is attached to the balance wheel.
U.S. Pat. No. 4,423,345, which issued to Nilsson on Dec. 27, 1983, discloses a magneto flywheel assembly which includes arcuate ceramic magnets of non-uniform radial thickness. A rotor for the flywheel is made of soft material. The magnets of the magneto flywheel have a set of radial poles of alternating polarity, and another set of opposite poles directed towards the cylindrical periphery of the magneto rotor. A ferromagnetic band of deflectible material with the surface projection is disposed between the rotor and the magnets.
U.S. Pat. No. 5,015,901, which issued to Phelon et al on May 14, 1991, describes a rotor of a magnetmotive device. It has a discreet permanent magnet and a ferromagnetic core injection molded within a synthetic plastic body in the form of a flywheel. The core is of integral laminar construction and includes hub and counterweight portions and a pair of radially extending, circumferentially spaced arm portions. At their outer ends, the arm portions terminate in pole shoes with opposed, undercut edges to retain the discrete permanent magnet therebetween. Each of the arm portions has a laterally extending shoulder portion and, at their inner ends, connect to the hub by narrow neck or stem portions which are resiliently flexible. From the center of rotation of the rotor, the stem portions are each disposed along a given radius. Each of the arm portions of the core is characterized by a configuration and distribution of mass so that its center of gravity is located outward of the given radius whereby centrifugal force generated by high speed rotation of the rotor exerts opposing, inwardly directed forces on the arm portions for clamping the magnet therebetween.
U.S. Pat. No. 4,980,592, which issued to Olmr et al on Dec. 25, 1990, discloses a flywheel magnet rotor assembly. The assembly comprises a core, a magnet, two pole shoes and a molded resin disk. The core is comprised of metallic nonferromagnetic material forming a general can shape with apertures through a first wall. The magnet is sandwiched between the pole shoes inside the can shape and portions of the pole shoes extend out of the apertures. The molded resin disk substantially surrounds the core.
U.S. Pat. No. 4,916,343, which issued to Umemoto et al on Apr. 10, 1990, discloses a multi-pickup sensor bracket for a magneto. An engine igniting signal generation apparatus comprises a flywheel rotatable with the crank shaft of an internal combustion engine, a field magnet attached to the flywheel, and a plurality of pickup devices provided facing the field magnet to produce ignition signals in synchronism with the rotation of the flywheel. The cores of the pickup devices are formed by a substrate body of one piece; each coil wound around the cores connects to a terminal, to output the ignition signals, and is covered with an insulating material.
U.S. Pat. No. 4,433,473, which issued to Benedetti on Feb. 28, 1984, describes a process for manufacturing a flywheel magneto. The method is disclosed for manufacturing a flywheel magneto of the radial magnetic flux type for motor bicycles, motor scooters and the like, which comprises the steps of forming a subassembly comprised of a ring, the magnets, the pole shoes by scotching the ring on a plurality of wedges placed around a cylindrical body whereafter the pole shoes and an inner ring of a metallic nonmagnetic material are positioned and a punch rams all these component parts forcibly together. Finally, the subassembly so composed is surrounded by a casting of the nonmagnetic material.
U.S. Pat. No. 4,295,070, which issued to Johansson on Oct. 13, 1981, discloses a means for providing a mechanically definable selected trigger interval in a flywheel magneto. The ignition apparatus for internal combustion engines provided with flywheel magnetos, the ignition spark interval is purely mechanically provided at the manufacturing stage. In the direction of rotation, the edges of both pole shoes and core legs which meet each other are sharply defined. The pole shoe, first in the direction of rotation, is formed so that it substantially coacts with the leg, second in the direction of rotation, when the leading edge of the second pole shoe comes into coaction with the front edge of the leg situated first.
U.S. Pat. No. 4,877,986, which issued to Shimizu on Oct. 31, 1989, describes a rotor of a magnetic generator. The rotor has a plurality of permanent magnets disposed on an inner surface of a peripheral wall of a bowl-shaped flywheel. The permanent magnets are held in place by a magnet holding cylinder having plural outward protrusions formed in a radial direction at a first open end and an outward flange formed on a second open end thereof. Resin is provided to fill empty spaces of this assembly so that the magnets, the magnet holding cylinder and the flywheel are made of an integral piece thereof.
It would be beneficial if a magnet wheel could be provided which firmly holds the magneto in place and is easy to accurately position the magneto in their proper locations.